Medical Image Display

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Medical Image Display

• Bradley Hemminger
• School of Information and Library Science
• Department of Radiology,
• University of North Carolina, Chapel Hill
• http//ils.unc.edu/bmh
• bmh_at_ils.unc.edu

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Medical Image Display

• Digital Values Human Observer
• Observer makes decisions
• Decisions affect patient care/treatment
• Results in different patient outcomes.

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Basic Perception Issues

• Color or Grey Scale to Use?
• Standardizing the Grey Scale
• Perceptual Linearization
• Different types of Displays (CRT, flat panel)
• Calibration

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PACS multiple sources and destinations

LAN
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Consistent Grayscale
Acquire
Display
Print
Slide courtesy of David Clunie, ComView
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Image Presentation Integrity
Goal Images look the same independent of the
display system or method used to present the
images. DICOM Standards supporting this -
Grayscale Standard Display Function - Softcopy
Presentation State Storage AAPM guidelines -
Display Quality for Electronic Displays
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Perceptual Linearization
Ambient Light
Perception of Contrast By Human Visual System
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Display Card Values (0-255, 0-1023) Laser Printer
Values (0-255, 0-4095)
Display Card
Computer
Analog Voltage
Luminance on Monitor or through film on Lightbox
Computer Digital Values (0-255, 0-4095, ...
0-65535)
Perceived Brightness by human observer
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Computer
Display Card
Characteristic Curve
CSF
Contrast Sensitivity Function (CSF) Transfer
function describing the change in luminance
required to see a contrast threshold at a given
luminance level.
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Image Display and Interaction

• Single Images
• Alternators
• Hanging Protocols
• Staged Interactions (Mammo Screening)
• Studying Users to optimize CHI.

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Image Enhancement

• Intensity Windowing
• Unsharp Masking
• AHE
• MUSICA

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Novel Display technologies

• Cine/stack
• 3D
• Virtual reality
• Fusion

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